KR20050029882A - Method for mending and reinforcing concrete construction by high-pressure dry spraing system - Google Patents

Abstract

A method for repairing and reinforcing a concrete construction by high-pressure dry spraying method of powder-type polymer mortar is provided to increase load carrying capacity and to expand the life span by fixing a steel bar with a cement anchor and a reinforcing set anchor and then filling a section by dry-spraying the section at high pressure. A method for repairing and reinforcing a concrete construction by high-pressure dry spraying method of powder-type polymer mortar is composed of a surface arranging step, a grooving step, a step for mounting a steel bar and an anchor, a high-pressure water cleaning and wetting step, a spray construction step, a surface finishing step, and a step for coating an anti-neutralizing agent with wear resistance and a water repellent. The spray construction step comprises courses for supplying automatically powder polymer mortar from an automatic feeding silo(60) to a high-pressure transfer hose(30) by a high-pressure pump(40); pre-wetting primarily the polymer mortar with the water of 1~2% inputted from a first water tank(50); transferring the pre-wetting polymer mortar through the high-pressure transfer hose to an injection nozzle(10) by compressed air(A) and a power generator(M); and mixing suddenly the polymer mortar reaching the injection nozzle with the water of 10~13% inputted from a second water tank(20) and spraying the mixture of the water and the polymer mortar at the speed of 80~100km/h.

Description

Method for mending and reinforcing concrete construction by high-pressure dry spraing system}

The present invention relates to a method for repairing and reinforcing concrete structures by a high pressure dry spray method of powder-type polymer mortar, surface preparation of concrete structures, reinforcing bar and anchor installation, antirust agent construction, high pressure water washing, spray construction, cross-section filling, The present invention relates to a spray construction process for repairing and reinforcing concrete structures comprising a surface finish, a water repellent and an anti-neutralizing agent coating having abrasion resistance.

After construction, concrete structures are continuously subjected to external loads or differential forces, and cracks are generated from areas with weak structural strength by repeated expansion and contraction due to external temperature changes. In addition, when the pH of concrete structures is lowered from 12 to 9 or less due to carbon dioxide gas, water or salt in the air over time, neutralization of the alkali proceeds rapidly due to the neutralization of alkalis. As the compressive strength and the tensile strength of the reinforcing bar drop, the cracking of the reinforced concrete increases, causing the peeling of concrete.

In the conventional general method of repairing abnormal cracks and peeling and peeling of concrete, which is generated from reinforced concrete civil structures and building structures, a chemical injection nozzle is inserted into the cracked part when a crack occurs in the concrete structure. The solution supplied from the medicinal solution was injected and filled, or various repair materials were plastered by hand or manually by brush. However, this conventional method has a problem that the work is difficult, and in the case of the ceiling surface, the adhesion is low, the maintenance effect is low, and the work time is long, and the work efficiency is lowered. In addition, since the adhesive patching agent is applied after several steps of overlapping patching, neglecting the work even in one step may affect the overall quality.

Therefore, in recent years, a wet spray method has been developed and used to improve the quality and workability as a method of repairing reinforced concrete structures.

However, in the wet spraying method, the maximum transport distance between the spray machine and the nozzle is less than 60 m, so the transport pump travel distance is too short, and it takes a lot of time to prepare and clean the work at the start, stop, and end of the work. When repairing concrete structures that are inaccessible to machines or vehicles, such as distant sewage boxes or high-rise towers with heights of 20m or higher, separate equipment such as lifts are required and materials and machines must be transported by manpower. The labor cost is not only high, but also in the workload, the maximum work volume per day was 6㎥, which was problematic in terms of economy.

The present invention was devised to solve the above problems and defects, the object of the present invention has excellent workability and excellent quality compared to the existing patching method in the repair and reinforcement of various concrete structures, the quality is wet It is more efficient than the spray method, so it is more efficient and easy to work. Also, the problems of wet spray method are workability, work efficiency, work speed, work accessibility, frequent parts change and mechanical failure, weighing and transportation, and excessive cleaning time. The present invention provides a method for repairing and reinforcing concrete structures by high-pressure dry spray method of powdered polymer mortar, which can solve the problems such as the requirement, the number of work factors, and the limitation of work load.

In order to achieve the above object, the repair and reinforcement method of the concrete structure by the high pressure dry spray method of the powdered polymer mortar of the present invention is a surface cleaning process, grooving process, reinforcing bar and anchor installation process, antirust agent construction process, high pressure water washing And in the repair and reinforcement method of the concrete structure consisting of a wetting process, spray construction process, surface finishing process, water repellent and anti-neutralizing agent coating process, the spray construction process is the first stage, the filling spray, the finishing spray Wherein each of the spraying process is a step in which the powdered polymer mortar is automatically supplied from the silo for automatic supply to the high pressure transfer hose by a high pressure transfer pump, at the same time 1 to 2% of water from the first water tank Primary hydromixing, wherein the primary hydromixed polymer mortar Is transferred to the injection nozzle through the high pressure transfer hose by means of air, and the polymer mortar which reaches the injection nozzle is instantaneously mixed with 10 to 13% of water introduced from the second water tank, and at a speed of about 80 to 100 km / h. It is composed of a step of spraying.

The repair and reinforcement method of the concrete structure by the high pressure dry spray method of the powder-type polymer mortar of the present invention is the reinforcing bar and anchor installation process reinforcement anchor drilling, reinforcement anchor installation, reinforcing steel installation, correction anchor drilling, Characterized in that the order of the rebar correction anchor installation.

In addition, in the present invention, the grooves are dug so that the reinforcing bar arrangement interval is 150 to 200 mm in the grooving process, and each groove is cut in a portion where the reinforcing bar is to be placed, and then the concrete is broken by cutting the concrete to form a line like the main bar. It is also characterized in that it is arranged so that the cover can be secured sufficiently.

Hereinafter, the repair and reinforcement method of the concrete structure by the high pressure dry spray method of the powdered polymer mortar according to the present invention will be described in detail.

Damaged concrete structures, such as lowering the load capacity of the structure or peeling and falling concrete, first clean the surface of the concrete structure by chipping or sandblasting the surface by a breaker, a rock drill, or the like.

After grooving chipping to insert reinforcing bars and reinforcing materials on the surface of the concrete structure, the reinforcing bars and anchors are installed to increase adhesion. At this time, the reinforcing bar and anchor installation process is preferably in the order of reinforcing anchor drilling, reinforcing steel anchor installation, reinforcing steel installation, correction anchor drilling, reinforcing steel anchor installation.

Installation of the reinforcing anchor selects and fixes various anchors such as anchors by taka, anchors by drills or cement anchors for reinforcing bars for reinforcing reinforcing bars depending on the thickness of the cross section.

The reinforcing bars and anchors are fixedly attached to deep portions of the repair surface so that the sprayed mortar can be adhered well without using an adhesive aid. In addition, in order to strengthen the adhesive force and maintain the adhesion of the repair and reinforcement in the long term to fix the problem of lifting or dropping, fixing the Taka fixing pins, nails, screws, etc. in addition to the reinforcing bars and anchors.

In general, the wet spraying method does not require an adhesive, while the dry spraying method requires the use of an adhesive. The method of repairing and reinforcing the concrete structure by the high pressure dry spraying method of the powdered polymer mortar of the present invention can be performed without an adhesive aid. Is clearly distinguished from conventional wet and dry spraying methods.

Remove the rust of the fixed reinforcing bars, anchors, Taka fixing pins, nails, screws and the like. Thereafter, a rust preventive agent is applied to the rebar, anchor, and the like in order to prevent rust rust. At this time, it is effective to select and use a rust inhibitor used cement-based or epoxy-based.

After the antirust agent construction step, the surface of the repair surface and rebar, anchor Taka fixing pins, nails, screws, etc., removes foreign substances such as dust, washes with high-pressure water to make the repair surface wet, and then sprays them. The high pressure water washing after the rust inhibitor construction step to maintain the wet state is because it can prevent the phenomenon of lifting and cracking before the adhesive strength is maintained during the initial rapid drying after spraying the polymer mortar.

In the spraying step, 1 to 2% by weight, 26 to 28% by weight of cement, 68 to 72% by weight of silica sand, and 1 to 2% of mixed polymer of powdery butyl acrylate styrene polymer, styrene acrylic polymer, styrene butadiene polymer or acrylic polymer It is preferable to use the polymer mortar for spraying which mixed 2 weight%.

Here, the admixtures that may be used for the polymer mortar include AE agents, water reducing agents, fluidizing agents, high performance water reducing agents, hardening accelerators and retardants, rebar rust inhibitors, foaming agents, waterproofing agents, etc., and the size of the silica sand particles is 4 mm or less (4 to 4). 5 Rosa) is preferably used. Since the amount of water input affects quality, yield and workability, it is adjusted according to the nozzleman's skill level. When spraying, an appropriate preparation time of 3 to 5 minutes is required for adjusting the flow rate and adjusting the rebound.

The polymer mortar to be used in the present invention is a powdery inorganic reactivity, which is fine as a composition containing 1 to 2% powdered polymer, 26 to 28% cement, 68 to 72% silica sand, and 1 to 2% admixture. Therefore, the density is smoother than that of the hand plastering method, and the surface density is improved, which can suppress the penetration of water, carbon dioxide, and chlorine ions, which are the causes of concrete neutralization, and increase strength, freeze-thawing resistance, excellent adhesion, It has flame resistance and chemical resistance, which increases the load capacity of the structure and maintains durability in the long term.

Spray device used in the repair and reinforcement method of the concrete structure by the high pressure dry spray method of the powdered polymer mortar of the present invention is a high pressure dry spraying device, as shown in Figure 2, the injection nozzle 10, the first article Tank 50, second water tank 20, high pressure transfer hose 30, high pressure transfer pump 40, silo 60 for automatic supply of polymer mortar, compressed air (A), generator (M) It consists of a remote control (R). The high pressure dry spray device may be configured by variously changing the size of the silo to 3㎥, 6㎥, 12.5㎥ or 22.5㎥ according to the working conditions.

The high-pressure dry spray device is capable of speed control with a lotus spray (WM05-3) type. In particular, when a vulkolan nozzle (using vulkolan nozzle 32, manufactured by WernerMader GmbH) is used, the maximum capacity is 0.5 to 2.2㎥ / h, the maximum particle size is 8mm, the maximum conveying distance is 150m (generally 120m), the required electricity amount is 3Kw, 400v / 50cycle · 16A, and the nozzle can be used depending on the type of work and the particle size of silica sand.

When spraying the polymer mortar in the high pressure dry spraying apparatus used for the repair and reinforcement method of the concrete structure by the high pressure dry spray method of the powdered polymer mortar according to the present invention, the compressed air is 7 kg / cm 3 or more, and 4 to 9 m 3 / min, and moisture is preferably supplied at a rate of about 37 ± 3% W / C. The maximum one-time construction thickness of the lower surface of the slab using the high pressure dry spray device is 10 cm for the local cross section, 4 cm for the entire surface is possible.

The process in the high pressure dry spray device is as follows.

That is, the mixed polymer mortar is stored in a powder state in the silo 60 and is automatically supplied to the high pressure transfer hose 30 by the automatic transfer device and the high pressure transfer pump 40 provided in the silo 60. The polymer mortar is supplied to the high pressure transfer pump 40 and is prewet with 1 to 2% of water introduced from the first water tank 50. At this time, 1 to 2% of the water supplied prevents layer separation due to the weight difference between the mixtures of the polymer mortar and increases the reactivity, thereby facilitating the movement of the polymer mortar in the high pressure transfer hose 30. .

The primary hydro-mixed polymer mortar receives the compressed air (A) of 7 kg / cm 3 or more in the high-pressure transfer hose (30) 4 to 9 ㎥ per minute (min) by spray nozzle 10 in a mixed state Is transported toward. The polymer mortar reached to the injection nozzle 10 is instantaneously mixed with 10 to 13% of water introduced from the second water tank 20 while passing through the screw in the injection nozzle 10 to cause a polymer reaction, and about 80 to 100. It is sprayed at the speed of km / h.

The injection process of the high-pressure dry injection device is remotely controlled by a remote control (R) connected to the high-pressure transfer pump (40).

Therefore, unlike the wet spray method in which the mortar and the water are mixed and then transported and sprayed, the high pressure dry spray method of the powdered polymer mortar of the present invention is instantaneous in the high pressure transfer pump and the nozzle without the need for a separate mixing process with water. It is characterized by being mixed and stirred.

As described above, the construction for the repair and reinforcement of the concrete structure by the high pressure dry spray method of the powder-type polymer mortar of the present invention is carried out in two stages: the first spraying and the filling spraying and the finishing spraying.

First, in order to increase the surface adhesion of the polymer mortar and to form an adhesive layer, the primary spray is sprayed through the above-described method on the repair surface of the concrete structure and the fixed reinforcing bars, anchors, Taka fixing pins, nails, screws, and the like. Prior to spraying the mortar is hardened to form a filling layer by injecting and filling the polymer mortar by the injection method through the above steps so as to cover the back of the reinforcing bar, anchor, Taka fixing pin, nail, screw, and the like. Leave it for at least 3 hours to cure, then finish the spray by spraying through the above steps or finish the surface with a plastering trowel.

The maintenance surface of the concrete structure filled with the spray construction is cleaned with a plastering trowel and gently rubbed with a sponge moistened with water within 5 minutes to finish the surface not to be shiny. This is because the shiny surface when dried in the trowel plastering state can be a bumpy surface during the next coating, the surface is smoothed by the sponge finish effect.

After curing after the surface finishing step is coated with a water-repellent agent on the concrete surface. The water repellent coating is intended to maintain long term durability. In the present invention, it is preferable to use a water repellent made of a mixture of silane or siloxane.

When the concrete structure to be repaired and reinforced is a tunnel or underground roadway, acrylic or epoxy coating agents are respectively applied to enhance water resistance after cleaning the water repellent coating step and to increase resistance to carbon dioxide, sulfur dioxide, ammonia gas, and melting agent. It is preferable to apply a protective coating to 150-180 micrometer thickness by coating twice.

The repair and reinforcement method of the concrete structure by the high pressure dry spray method of the powder-type polymer mortar according to the present invention by spraying the front, top, bottom 0.5 to 1m thickness at high pressure in the spray construction step, the density of the repair section is hand plastering method It is high in comparison with water, salt and chemical resistance. Therefore, there is an advantage in repairing and reinforcing bridges, tunnels, overpasses, concrete walls, offshore structures, harbor facilities and post-fire concrete structures, and it is particularly advantageous for repairing and reinforcing coastal and dam structures due to its excellent resistance to salt and hydration heat. In addition, it is excellent in waterproof performance compared to general mortar.

〈Dry vs. wet spray method〉

Comparing the high pressure dry spray method of the powder-type polymer mortar according to the present invention with the conventional wet spray method is as follows.

Table 1.

Wet method Dry method Remarks Distance between machine and construction surface (m) 60 m 150 m 120 m normally One set of people at work 6 people 4 people Work preparation and cleaning time 3 hours 30 minutes Equipment blockage (failure) plenty None Possible to clean the nozzle Premix with water need Unnecessary Daily workload (up to 8 hours) 6㎥ (0.2∼1.2㎥ / h) 12㎥ (0.5∼2.2㎥ / h) Opening time (20 ℃) 80 minutes 70 minutes End time (20 ℃) 140 minutes 120 minutes Rebound amount (%) 5% or less below 10 Spraying distance (m) 0.5-1m 0.5-1m same Packing unit 25 kg, 1 ton 25kg, 1ton, silo For dry, use silo auto feeder Lotus Tate Preparation need Unnecessary Particle size

As shown in the table above, the high pressure dry spray method of the powder polymer mortar of the present application has a distance of up to 150m, and can be accessed up to 300m in the case of flat land, and a structure of up to 100m in height can be accessed by manpower. There is an advantage to work alone. In addition, in the wet spraying method, since the polymer mortar mixed with water is present in the transfer hose, the mixture in the hose hardens when the work is stopped or the machine breaks down. However, this method does not have this problem. In addition, in the wet method, at least 6 people should be operated in one pair, but this method is economical because it is operated in one pair of four. In addition, this method shows the same quality compared to the wet spray method during construction, it can be called an economical and excellent method.

Although the method of rebounding is slightly more than 10% compared to the wet method of 5% or less, this value can be sufficiently lowered according to the nozzleman's skill.

〈Quality Comparison by Dry and Wet Spraying Technique〉

When comparing the quality repaired by the high pressure dry spray method and the conventional wet spray method of the powder-type polymer mortar according to the present invention.

Table 2.

deflation Wet Remarks Compressive strength (㎏ / ㎠) 7 days More than 600 More than 400 Drying has no quality change after 28 days. 28 days More than 650 500 or more 90 days More than 650 More than 550 Flexural strength (㎏ / ㎠) 7 days over 90 over 90 Drying has no quality change after 28 days. 28 days 100 or more 100 or more 90 days 100 or more 120 or more Adhesion Strength (㎏ / ㎠) 7 days 20 or more 20 or more 28 days 25 or more 25 or more Dynamic modulus of elasticity (㎏ / ㎠) 28 days 350,000 290,000 Powder mortar surface density (g / cm 3) 2.0 2.0

As shown in the table above, high pressure dry spray method of the powdered polymer mortar of the present application which has excellent adhesiveness and no need for adhesive construction and multi-stage construction, excellent workability and excellent slab bottom construction and reinforcing the back of rebar It is much better than the wet spraying method in the dynamic modulus, and the same in other flexural strength, adhesion strength and powder mortar surface density.

In the high pressure dry spray method of powder type polymer mortar according to the present invention, when a repair section is severely deteriorated, after drilling to a fresh concrete section using various anchors, the anchor construction is repeated and repeated vibration and fatigue load and long period of elapsed time. This reduces the adhesive performance and prevents the repaired part from falling off due to the lift-up of the repair section.In addition, the reinforcement can be cemented when the load capacity of beams, slabs, columns, and tunnels is insufficient. Anchors, set anchors, tackle anchors, etc. are fixed by anchors to fill the cross section, so that the load capacity can be improved by 50% or more.

〈Load capacity analysis〉

By comparing and analyzing the results of the calculation of the basic load capacity and the common load capacity for the upper slab of the sewage culvert (2 × 2 × 2m), which is a concrete structure repaired and reinforced by the method according to the present invention, it was confirmed whether the repair and reinforcement effect ( Reinforcing bar 16Ø㎜, 20㎝ spacing, 2m width, collinear with the position of the main reinforcing bar, cement anchor fixing).

Table 3. Basic load capacity analysis before and after reinforcement

division Before reinforcement After reinforcement Reinforcement effect (%) Basic load capacity DB-24 DB-41 71

Reinforcement effect (%) = (After reinforcement-before reinforcement) × 100

                     Reinforcement

Table 4. Comparison and analysis of common load capacity before and after reinforcement

division Before reinforcement After reinforcement Reinforcement effect (%) Common load capacity Strain DB-22 DB-41 86 Sag DB-29 DB-66 127

Reinforcement effect (%) = (After reinforcement-before reinforcement) × 100

                      Reinforcement

As a result, after the reinforcement, the basic load capacity increased by 71% and the common load capacity by at least 86%.

That is, the repair and reinforcement method of the concrete structure by the high pressure dry spray method of the powder-type polymer mortar according to the present invention was determined to sufficiently express the reinforcement effect as well as the repair 70% or more.

The present invention is a dry spray machine without fixing the inorganic reactive powder-type polymer mortar without adhesive aid after fixing the reinforcement of the required amount of steel in various anchors in the repair and reinforcement of concrete structures degraded by various environmental and external factors such as neutralization, salt and salt By controlling the nozzle man's remote control by the machine connected with the automatic supply control device, it controls the formation of the adhesive layer, the filling layer of the reinforcing steel cross section and the spraying process at the finishing stage, and improves the load capacity by completing the cross section. It can be widely used in repairing and reinforcing concrete structures such as bridges, sewer culverts, underground roads, overpasses, tunnels, fired concrete structures, building foundations and underground parking lots, railway structures and subway structures.

Thus, the present invention is fixed to the RC structure lacking load capacity by cement anchor and reinforcement set anchor, and then dry spraying at high pressure to cross-section charging to increase the load capacity of the structure to make a stable structure to make a long-term life Extend it for use.

In addition, the present invention can be installed without the waste of manpower even in the structure of up to 150m distance and 100m in height, and because the one-time construction thickness is more than 1cm thick compared to the wet spray, It is economical to reduce.

In addition, the quality is not only superior to the wet method, but also the work efficiency is improved by more than 50% due to the improvement of the worker's fatigue and the increase of the working amount, and the rebounding amount can be sufficiently reduced by the skill of the nozzle man.

1 is a block diagram showing the repair and reinforcement process of a concrete structure by a high pressure dry spray method of powdered polymer mortar according to the present invention;

2 is a high pressure dry spray process diagram of a powder type polymer mortar showing the spray construction process of the repair and reinforcement method of the concrete structure by the high pressure dry spray method of powder type polymer mortar according to the present invention;

Figure 3 is a schematic diagram of the repair and reinforcement of the slab by the repair and reinforcement method of the concrete structure by the high pressure dry spray method of the powdered polymer mortar according to the present invention.

<Explanation of symbols for main parts of drawing>

10: spray nozzle 20: second water tank

30: high pressure transfer hose 40: high pressure transfer pump

50: first water tank 60: silo for automatic supply of polymer mortar

A: compressed air M: generator

R: Remote control 100: Reinforcing bar

110: cross section recovery part 200: cast steel

210: slab 220: chipping part

Claims (3)

Repair of concrete structure consisting of surface cleaning process, grooving process, rebar and anchor installation process, antirust agent construction process, high pressure water washing and wetting process, spray construction process, surface finishing process, water repellent and anti-neutralizing agent coating process And in the reinforcement method, The spray construction process is composed of two stages of the first spray, filling spray, finish spray, In each spray construction process, the powdery polymer mortar is automatically supplied from the auto supply silo 60 to the high pressure transfer hose 30 by the high pressure transfer pump 40, and at the same time, the first water tank 50 1 to 2% of water is added from the primary hydromixing step, and the primary hydrolyzed polymer mortar passes through the high-pressure transfer hose 30 by the compressed air (A) and the generator (M) and spray nozzles ( In step 10), the polymer mortar reaching the injection nozzle 10 is instantaneously mixed with 10 to 13% of water introduced from the second water tank 20 and sprayed at a speed of about 80 to 100 km / h. Repair and reinforcement method of the concrete structure by the high pressure dry spray method of powdered polymer mortar, characterized in that it comprises a step. The method of claim 1, wherein the reinforcing bar and anchor installation process is performed in the order of reinforcing anchor drilling, reinforcing steel anchor installation, reinforcing steel installation, correction anchor drilling, reinforcing steel anchor installation order. Repair and reinforcement method of concrete structure by high pressure dry spray method. According to claim 1 and 2, wherein the grooves are dug so that the spacing of the reinforcing bar is 150 ~ 200mm in the groove digging process, each groove is cut only to the site where the reinforcing steel is to be placed to break the concrete reinforcement A method for repairing and reinforcing concrete structures by high pressure dry spray method of powdered polymer mortar, which is arranged on the same line as the main reinforcing bars and the coating is sufficiently secured.